Delphi 判断fast report 是否存在未定义对象

Assigned（‘fastreport 对象’） Boolean; 返回 

sql.Fields[i].FieldName 获取列名

sql:='select * from table';
tmp_ADOQuery:=DLLMan.Exe_server_Query(sql);
for i:=0 to tmp_ADOQuery.FieldCount -1 do
 begin
    if Assigned(tfrxmemoview(main.frxreport1.FindObject(tmp_ADOQuery.Fields[i].FieldName))) then                                     
        tfrxmemoview(main.frxreport1.FindObject(tmp_ADOQuery.Fields[i].FieldName).Memo.Text:=tmp_ADOQuery.Fields[i].Asstring;
end;